A variety of minimally invasive instruments and related techniques have been developed for diagnosis and treatment of various ailments and conditions. Endoscopic procedures, such as Endoscopic Mucosal Resection (EMR), Endoscopic Sub-mucosal Resection (ESR), Polypectomy, Mucosectomy, etc., are minimally invasive methods for removal of abnormal or diseased tissue from a patient's body.
For example, a physician may excise sessile adenomas (i.e., tumors attached to a bodily surface) from the colon or other parts of the gastrointestinal tract using EMR. Minimally-invasive instruments may be inserted into a body lumen and used for resecting the target tissue while leaving the underlying tissue plane intact. Instruments like snares with a loop portion may be used to ensnare or surround the target tissue and resect it by tightening the snare and/or by energizing the snare and pulling the snare so as to cut the tissue.
A physician's ability to control the snare is an important factor that determines its effectiveness for resection. When a physician places a snare on the target tissue, many conventional snares have a tendency to slip off the tissue to be resected. Such snares may be unable to sufficiently grip the tissue and may require repeated efforts to capture the target tissue. If the physician is not able to properly control the snare, the target tissue may not be properly captured and resected. Improper placement of the snare may also lead to an irregular cut, or an angled cut and cause damage to the surrounding tissue. As a result, there may be unnecessary loss of blood and healthy tissue from a patient's body, which may further lead to difficulties in visualization and patient recovery.
Therefore, there exists a need for devices and methods that offer physicians better control to grip tissue effectively for consistent capture, excision, or removal of unwanted tissue without affecting the surrounding tissue.